Conductor stranding can be a bit confusing. Wire and cable is manufactured in a variety of configurations, not all wire is the same. The conductors for wire (aside from solid core) are made of multiple strands of fine wire bunched or twisted together.

1. Conductor stranding can be a bit confusing. Wire and cable is manufactured in a variety
of configurations, not all wire is the same. The conductors for wire (aside from solid
core) are made of multiple strands of fine wire bunched or twisted together. Conductor
stranding plays an important part of the flexibility and the performance life of the wire.
The more individual wire strands in a wire, the more flexible, break-resistant and stronger
the wire is. Hi flex applications where repetitive flexing is required use different
stranding than wire used to wire a building or home. "Off the shelf wire normally is
available in solid, 7 strand and 19 strand constructions which is fine for applications not
requiring flexibility or repetitive movement.
Repetitive flexing can cause conductor strands to break over time which lowers the
conductivity of the wire. Using higher strand wire helps eliminate this problem. High
strand wire is used in medical handheld devices, robotics and even headphones.
Many custom wire and cable manufacturers offer high strand wire which you cannot
obtain easily from distribution. For example, a 20AWG wire can be manufactured with a
solid conductor or solid core all the way to 168 strands. Knowing which conductor
stranding option will best suit your needs is important.
Identifying the conductor call out: A typical call out is XX (YY / ZZ). The "X" is the
gauge of the wire, "Y" is the number of strands and "Z" is the gauge size of those strands.
Once you understand what these numbers mean, identifying the conductor construction is
simple. A wire gauge chart is a handy tool to view wire gauge stranding options
The more common conductor stranding configurations are concentric (true concentric,
equilay concentric, unidirectional concentric, and unilay concentric), bunched and rope.
Rope stranding is conductor construction consisting of single strands assembled together
into concentric or bunched configurations. Rope constructions consist of concentric or
bunched members stranded together into the final concentric or bunched configuration.
Rope stranding has the advantage of increasing flexibility by using a larger number of
finer strands while maintaining a tighter diameter tolerance than a simple bunched
construction. Ropes are more evident in the larger AWG sizes, such as 8 AWG and
larger, but there are also many applications that require the flexibility of rope

2. constructions in the smaller gauges. Constructions vary and can contain hundreds or
thousands of strands.
Depending on the use, the type of conductor is important. Hi flex and load bearing
applications would require conductors with higher tensile strength such as alloys. Copper
conductors are normally for less rigorous flexing
Flexible wire is a term which can be interpreted in many ways from hi flex to the actual
flexibility of the wire. Letting your cable manufacturer know what your expectation is for
the flexibility of your wire or cable will help in choosing the right conductor stranding.
Calmont has manufactured extremely flexible large gauge wire and cable as big as 4/0
which is limp and flops over the end of a table. Of course insulation and jacket material
also plays an important role in making a flexible cable, but the conductor stranding is
where you start